I seem to have a proplem with riding my bike on a trainer. I remember this from last season when I got the trainer too. Just trying to do some maintainence cycling now that the weather has gotten too cold for my taste. I rode for hours this year outside and did a few olympic triathlons so I would say I'm pretty fit. Not like I'm just starting out and overdoing it. I run every other day and do a 1/2 hour on the trainer on the other days. I'm not really stressing when I'm riding on the trainer. Just working up a sweat, not even breathing hard for the most part. My runs are probably much more taxing physically. It's a magnetic trainer and it is my road bike with no adjustments beside the obvious, it has a trainer strapped to it now. The soreness is right where the achilles meets the calf. From my years of running this is a feeling that can eventually lead to a strain that puts me out of commission for a few weeks. I don't get it. Is it the always under load thing? Will I evetually work through this? About two week into this routine right now.